<?php
// album thumbnail
$thumb = dt_get_thumbnail(
    array(
        'post_id'	=> get_the_ID(),
        'width'		=> 290,
        'height'	=> 150,
        'upscale'   => true
    )
);

// big image
$big = wp_get_attachment_image_src(get_post_thumbnail_id(get_the_ID()), 'large');

// safe title
$title = esc_attr(strip_tags($post->post_excerpt));
?>

<a class="col_1-3 highslide" href="<?php echo $big[0]; ?>" title="<?php echo $title; ?>" onclick="return hs.expand(this)">
    <div class="loading-image">
        <img src="<?php echo $thumb['thumnail_img']; ?>" alt="<?php echo $title; ?>"/>
    </div>
    <div class="mask"></div>
</a>
<div class="highslide-caption">
    <?php the_excerpt(); ?>
</div>